华为编码规范和范例，对于编程人员值得一看，规范自己的代码，提高水平-Huawei coding standards and examples for programmers worth a visit, and regulate their own code to improve the level of

The primary aim of this book is to help the reader understand how the facilities offered by C++ support key programming techniques. The aim is to take the reader far beyond the point where he or she gets code running primarily by copying examples

QR codes (ISO/IEC 18004) are the type of 2D barcode with the sharpest increase in utilization in the last years. Fig. 1 shows some examples of QR code symbols.